Boiler blow down tank



Dec. 7, 1965 E. B. 'non 3,221,712

BOILER BLOW DOWN TANK Filed sept. 4. 196s INVENTOR,

EDWIN B. TIDD ATTORN EY United States Patent O 3,221,712 BOILER BLOW DOWN TANK Edwin B. Tidd, Park Ridge, Ill., assignor to International Telephone and Telegraph Corporation, New York, N.Y., a corporation of Maryland Filed Sept. 4, 1963, Ser. No. 306,494 1 Claim. (Cl. 122-379) This invention relates generally to blow down tanks for high pressure steam boilers, and has particular reference to an improved tank characterized by readily replaceable wear elements subjected to the scouring and eroding action of a blast of steam carrying boiler scale or other materials.

One of the principal objects of this invention is to provide an improved blow down tank characterized by structure for reversing the direction of the steam blast entering the tank, and providing at the point of reversal a readily replaceable wear element.

Another object is to provide a blow down tank having structure for reversing the direction of a blast of steam, and providing replaceable wear elements at the point where reversal takes place and along the reversed path of the steam.

Still another object is to provide in a blow down tank with readily replaceable structure for reducing the energy of a blast of steam, and for confining the abrasive effect of scale and other material carried by the steam blast.

Other objects and important features of the invention will be apparent from a study of the following specication taken with the drawing, which together describe and illustrate a preferred embodiment of the invention, and what is now considered to be the best mode of practicing the principles thereof. Other embodiments may be suggested to those having the benefit of the teachings herein, and such other embodiments are intended to be reserved especially as they fall within the scope and spirit of the subjoined claims.

In the drawing:

FIG. l is an elevational view of a blow down tank having the improvements according to the present invention embodied therein;

FIG. 2 is a plan view thereof, certain parts being shown in broken away section;

FIG. 3 is a plan view of an alternate form of the invention; and

FIG. 4 is an enlarged section taken through the embodiment seen in FIG. 3.

Referring now to FIG. 1, the improved blown down tank according to the present invention is referred to by the reference numeral 10, and includes a cylindrical vessel 11 having a flanged vent opening 12 at the top thereof. The vessel 11 is provided with a drain 13 at the bottom thereof to drain scale or sludge resulting from the blow down operation from within the tank 11. The drain 13 may be provided with a valve 14 as shown.

The vessel 11 has a cylindrical wall 16, and a steam line 17 connected to a steam boiler extends through and is supported by the wall 16. The steam line 17 extends in spaced substantially tangential relationship to the cylindrical wall 16 as seen particularly in FIG. 2.

Structure is provided for reducing the energy of a blast of steam introduced to the vessel 11 by the steam line 17 by reversing the direction of the blast of steam and for confining the wear effect of abrasive materials carried therein, and to this end a tube 18 extends though an opening 19 in the cylindrical wall 16, and is supported in wall 16 by weldments thereat. The tube 18 has a cross sectional area considerably larger than -the cross sectional area of steam line 17, and is arranged in nesting relationship wtih respect thereto.

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The tube 18 extends outside the wall 16, and has the end thereof provided with a flange 21 which is separated from a wear plate 22 by a sealing gasket 23. The wear plate 22 is held to the flange 21 by a plurality of through bolts 24.

The cylindrical vessel 11 is provided with a fitting 26 for introducing condensing water thereto, and the height of the water permitted within the vessel 11 is regulated by an overflow fitting 27 which is suitably baffled by a semicircular baille member 28 covering the opening 27 at the inside of the tank, and extending downward therefrom.

When it is desired to blow down the boiler, not shown, the drain valve 14 may be opened, and a quantity of 'condensing water introduced into the tank 11 at the cold water connection 26. When the boiler is connected to the steam line 17 the entering steam is changed in its direction within the tube 1S, the blast of steam being directed against the wear member 22. Since the steam carries in the blow down operation a quantity of abrasive materials such as scale, boiler compound and sludge or the like, the abrasive effect of such material is taken by the wear member 22. The reversal in direction of the steam blast also reduces greatly the energy therein, the steam being enabled to expand within the larger diameter tube 18, and subsequently within vessel 11. The water entering at the cold water fitting 26 condenses the steam, so that it can leave the vessel 11 by the drain line 13. Any vapors resulting from the blow down operation can readily be vented through the opening 12 at the top of the tank 11.

Referring now to FIGS. 3 and 4 of the drawing, lthere is shown a second embodiment of the invention referred to generally by the reference numeral 25. In this embodiment, -the cylindrical wall 16 of the cylindrical vessel 11 has a short length of tubing 29 which is welded at 31 to the outer wall of the cylindrical vessel 11. The end of the tubing extending outside of vessel 11 has a flange 32 at the end thereof, and a wear tube 33 is fitted within the extension 29, the wear tube having a flange 34 at the outer end thereof. A wear plate 36 closes the end of the tube 33, and a steam type gasket 37 is interposed between the wear plate 36 and the flange 34 at the end of the wear tube 33. A similar gasket 38 is interposed between the flange 34 at the end of the wear tube 33, and the flange 32 is Secured `to the tube 29. A plurality of cap screws 39 make a steam-type fitting as seen in FIG. 4.

As with the embodiment seen with respect to FIGS. 1 and 2, the energy of the steam entering the cylindrical vessel 1-1 and introduced into 4the :wear tube 33 has its energy reduced considerably by the reversal in direction of the steam blast, at the same time the scale and other material carried by the blast of steam Ibeing `directed both against the wear plate 36 and against the interior of the wear tube 33. It will be remembered that the steam line 17 in this case also, is nested Within the wear tube 33.

yWhen the Wear plate 36 and the wear tube 33 have been abraded or otherwise worn by the blast of steam and the materials carried thereby, both the Wear tube and the wear plate 36 can be readily exchanged for new members, all without the need of dismantling the entire tank.

Having thus described the invention in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains to make and use the same, and having set forth the lbest modes contemplated of carrying out the invention, the subject matter regarded as being patentable is particularly pointed out and distinctly claimed, it being understood that equivalents or modifications thereof, or substitutions for, parts of the above specifically described embodiments may be made without departing from the scope of the invention as set forth in what is claimed.

I claim:

In a blow down tank for a steam boiler, a drain at the lower end of said tank for boiler sludge and scale, a steam line adapted to connect said blow down tank to said steam boiler, said steam line being supported by a wall of said blow down tank, and means for reducing the energy of a blast of steam introduced to said tank -by said steam line by reversal of the direction of said blast and for confining the wear effect of abrasive materials carried by said blast of steam comprising a tube of larger cross sectional area than said steam line, said tube being supported by the wall of said blow down tank and extending outward beyond said wall, a flange located at the end of said tube protruding beyond said wall of said blow down tank, a wear tube nested :within said tube of larger cross sectional area and having a ange thereon adapted to bear against the ange of said tube protruding beyond References Cited by the Examiner UNITED STATES PATENTS 1,396,939 11/1921 Miller 122-396 X 1,606,032 11/1926 Kolstrand 181-53 X 1,668,807 5/1928 Hawley 122-396 1,917,542 7/1933 Ploen 181-53 2,357,156 8/1944 Wilson 165-142 PERCY L. PATRICK, Primary Examiner.

KENNETH W. SPRAGUE, Examiner. 

